Method and apparatus for hanging well pipe



Jan, 24, 1967 w. L. TODD 3,299,951

METHOD AND APPARATUS FOR HANGING WELL PIPE Filed April 11, 1963 11 Sheets-Sheet 1 INVENTOR WILLlAM L. TODD ATTORNEY Jan. 4, 1%? w. 1.. TODD 9 13 METHOD AND APPARATUS FOR HANGING WELL PIPE Filed April 11, 1963 ll Sheets-Sheet 2 INVENTOR WILLIAM LTODD ATTORNEY Jan. 24, 1967 w. L. TODD 3,299,Q51

METHOD AND APPARATUS FOR HANGING WELL PIPE Filed April 11, 1963 ll Sheets-Sheet :3

22 p24 N24 .8O 62 INVENTOR WILLIAM LTODD ATTORNEY Jan. 24, 1967 w. L. TODD 3,299,951

METHOD AND APPARATUS FOR HANGING WELL PIPE Filed April 11, 1963 ll Sheets-Sheet 4 36 *04 36 INVENTOR L34: --43 WILLIAM 1.1000

Jan. 24, 1967 w. L. TODD 3,29%51 METHOD AND APPARATUS FOR HANGING WELL PIPE Filed April 11. 1965 11, Sheets-Sheet 5 73 43 7 2O 6O '11 82 J K52 -43 65 /22 r ,--22o 7o- INVENTOR a WILLIAM L.TODD

ATTORNEY Jan. 24, 1967 w. L. TODD 4 3,299,951

METHOD AND APPARATUS FOR HANGING WELL PIPE Filed April 11, 1963 1], Sheets-Sheet 6 60 220 A 7o 8 202 '40 82 I H4 H4 L /H6 -52 HO 75- v INVENTOR WILLIAM L.TODD

ATTORNEY Jan. 24, 1%? w. 1.. TODD 3,29%,953

METHOD AND APPARATUS FOR HANGING WELL PIPE Filed April 11, 1963 ll Sheets-Sheet 8 V d i/ sas I ll 120 120 INVENTOR WILLIAM L. TODD ATTORNEY Jan. 24, 197 w. L. TODD 3,299,@51

METHOD AND APPARATUS FOR HANGING WELL PIPE Filed April 11, 1963 ll Sheets-Sheet 9 E FEE 19a as; 220 202 Q 187 N 202 L i l :98

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l 202 mvemon 4 1, 192 WILLIAM L.TODD

184 BY M g ,7W..

. I 1 H 181 ATTORNEY Jan. 24, 197 w. L. TODD 3,299,%1

METHOD AND APPARATUS FOR HANGING WELL PIPE Filed April 11, 1963' ll Sheets-Sheet 1O m TEH E?EZ m5 ATTORN EY WILLIAM L.TODD

396? w. L. TODD 3,293,951

METHOD AND APPARATUS FOR HANGING WELL PIPE Filed April 11, 1963 11 Sheets-Sheet 1].

:81 so 202 i8 1 ZOZh INVENTOR WiLLlAM L.TODD

ATTGRNEY Patented Jan. 24, 1967 3,299,951 IVE'IHGD AND APPARATUS FOR HANGING WELL PIPE William L. Todd, Houston, Tex., assignor to FMC Corporation, San Jose, Calif., a corporation of Delaware Filed Apr. 11, 1963, Ser. No. 272,313 26 Claims. (Cl. 166-.5)

The present invention pertains to wells and more particularly to methods and apparatus for assembling well elements.

An object of the invention is to provide an improved method and apparatus for hanging well pipe.

The present invention provides a method and an apparatus for hanging well pipe, such as casing, and, more particularly, a method for hanging a string of casing with a mandrel hanger, or with a slip hanger if the string cannot be hung with the mandrel hanger. The invention also contemplates a remotely controlled slip-hanger-andcasing-cutter tool that can be supported in a convenient location in readiness for use if needed but which can be removed therefrom if the string is hung with the mandrel hanger.

The method and apparatus of the subject invention are especially useful for hanging casing in an underwater borehole from the surface of the water. In an underwater completion operation, after the support casing has been set in the hole and cemented and the wellhead has been attached thereto, the next step toward completion of the well is to hang the casing string. If no problem is involved in lowering the casing into the hole, the simplest and the most convenient and economical way to hang the casing string is to attach a mandrel hanger to the string a predetermined distance above the lower end thereof and to land this hanger in the wellhead. A problem does arise, however, when the casing sticks in the hole before the mandrel hanger can be landed in the wellhead.

As is well known, this sticking may occur since the borehole frequently is not perfectly straight, but is in the form of an extended helix or spiral, and since the wall of formations surrounding the hole is coated with drilling mud. As a string of casing is run into such a hole, it drags against the wall, frequently becoming impossible to move simply because of tight engagement with the wall, or because it partially embeds in a sticky formation or in the drilling mud. When a casing sticks in this manner, it usually resists either upward or downward movement. Thus, with a mandrel hanger connected in and constituting a part of the immovable string of casing, it is impossible to lower the string so as to land the mandrel hanger in the wellhead.

The present invention overcomes their difficulty by providing a method and apparatus for hanging casing whereby, if the casing does not stick, a mandrel hanger connected to the string of casing can be landed and used to hang the casing string, but if the hanger does stick, a readily available slip hanger can be used for hanging the string, and whereby in either instance, the unused hanger is retrievable.

Accordingly, it is another object of the present invention to provide a method and apparatus for hanging casing with a mandrel hanger, or with a slip hanger if the casing cannot be hung with the mandrel hanger.

Another object is to provide a method and apparatus for hanging casing even if the casing becomes stuck in the borehole and cannot be moved.

Another object is to provide a slip-hanger-and-casingcutter tool that is remotely controllable.

Another object is to provide a casing tool, including a slip hanger and casing cutter, that can be suspended in a well about a string of casing being run into a well and which can be used if the casing resists movement during the running operation.

Another object is to provide a casing tool, including a slip hanger and easing cutter, that is retrievable in whole or in part depending on whether or not the slip hanger is used.

Another object is to provide a casing tool including a slip hanger and casing cutter that are normally retained in retracted positions but which can be moved into operating positions by remote control while the tool is suspended deep within a well.

Another object is to provide a casing tool, of the type described in the preceding paragraph, that protects the cutter blades and slips in their retracted positions.

Another obiect is to provide a slip-hanger-and-casingcutter tool and a mandrel hanger that can move relatively to each other with the hanger inside the tool.

These, together with other objects, will become apparent upon reference to the following description and the accompanying drawings, in which:

FIGURE 1 is a side elevation of a slip hanger and casing cutter tool constructed according to the present invention.

FIGURES 2A, 2B, 2C, 2D, 2E and 2F, when placed in end-to-end relation in alphabetical sequence with 2A at the top and 2F at the bottom, constitute an enlarged fragmentary longitudinal section of the tool of FIG. 1, with a sleeve of the tool being in retaining position and with a portion of the tool between FIGS. 2A and 2B being broken away.

FIGURES 3A, 3B, 3C, 3D, 3E and 3F are similar to FIGS. 2AF except that they illustrate the tool with its sleeve in retracted position, and that fragmentary sections of an adapter and of a casing string are also illustrated.

FIGURE 4 is an enlarged, fragmentary transverse section taken along line 44 in FIGURE 2C.

FIGURE 5 is a fragmentary transverse section taken along line 55 in FIGURE 2F.

FIGURE 6 is a fragmentary side elevation as viewed from a position indicated by line 66 in FIGURE 5.

FIGURE 7 is a fragmentary transverse section taken along line 77 in FIGURE 2F.

FIGURE 8 is a longitudinal diametric section of an underwater Well installation showing the casing tool of the present invention and a string of casing in side elevation, this view being referred to in the following description to illustrate several steps of the subject method.

FIGURE 9 is a fragmentary longitudinal section of a portion of the well installation, enlarged from FIGURE 8, and useful in explaining other steps of the method.

FIGURE 10 is a still further enlarged, fragmentary longitudinal section of the surface conductor and adapter and side elevation of the casing string and the tool just as the latter is being actuated by engagement with the adapter.

FIGURES 11-15 are longitudinal diametric sections of the Wellhead and han er bushing of the present installation and primarily side elevations of apparatus in the wellhead, these views being referred to hereinafter in describing the present method.

Referring more particularly to FIGS. 1 and 2AF, a casing tool embodying the present invention is generally identified by the numeral 20. The tool includes a tubular support housing 22 having an upper section 24 (FIGS. 1 and 2A-D). This upper section includes a cylindrical upper element 25 (FIGS. 2A, B) provided with external threads on its upper end; a cylindrical intermediate ele-' ment 26 (FIGS. 2B, C) threaded into the lower end of the upper element 25 and providing an upwardly facing, internal annular shoulder 28, a plurality of circumferentially spaced, longitudinally extended slots 29 extending radially through the intermediate element, and outwardly opening recesses 30 extending upward from the slots; and a cylindrical lower element 32 (FIGS. 2C, D) threaded into the lower end of the intermediate element 26 and hav' ing an upwardly facing internal annular shoulder 34, and internal cylindrical wall 35 extending upward from said shoulder 34, and adjacent its lower end an external annular flange 36.

The support housing 22 of the casing tool 2!) also includes a lower section 40 (FIGS. 1 and 2C-F) including a cylindrical upper member 42 (FIG. 2C) surrounding the lower element 32 of the upper section 24 and slidably resting on the external flange 36; a cylindrical first intermediate mem'ber 43 (FIGS. 2C, D and E) threaded onto the lower end of the upper member 42 and having an internal annular upper shoulder 44 (FIG. 2D) in closely adjacent spaced relation to and below the lower element 32 of the upper section 24; a cylindrical second intermediate member 46 (FIG. 2E) threaded into the lower end of the first intermediate member 43 and providing a lower shoulder 48 spaced below the upper shoulder 44 and an internal cylindrical wall 49 extending downward from the shoulder 48, and a base member 52 threaded onto the lower end of the second member and providing an inwardly projecting radial flange 54 underneath the second intermediate member 46. An annular roller bearing 56 (FIG. 2D) is positioned between the upper shoulder 44 of the intermediate member 43 of the lower section and the lower element 32 (FIG. 2C) of the upper section so that the upper and lower sections 24 and 40 (FIG. 1) are interconnected for rotary movement relative to each other.

A cylindrical retaining sleeve 60 (FIGS. 1, 2BF, 4 and is axially slidably received within the support housing 22 (FIGS. 2B-F) and includes an upper portion 62 (FIGS. ZB-D) having an external annular end flange 63 (FIG. 2B) above and confronting the internal shoulder 28, a plurality of circumferentially spaced, longitudinally extending windows 64 (FIGS. 2C, D) individually aligned with the slots 29 (FIG. 20) so that a corresponding window and slot are intersected by a common plane extending radially and lengthwise through the support housing, and a counterbored lower edge 65 (FIG. 2D). Circumferentially spaced, upper shear pins 67 (FIG. 2B) extend radially through and interconnect the upper portion of the sleeve 60 and the intermediate element 26 of the housing, it being note-d that these pins are located slightly above the recesses 30 (FIG. 2C) in the housing.

The retaining sleeve 60 (FIGS. 2B-F) also includes a lower portion 70 (FIGS. 2D-F) having a grooved upper end 71 (FIG. 2D) interfitted with the lower edge 65 of the upper portion 62, an external annular shoulder 73 (FIGS. 2D, E) above and confronting the lower shoulder 48 (FIG. 2E) of the housing 22, a plurality of perfora tions 74 (FIG. 2D), and a lower end 75 (FIG. 2F). Circumferentially spaced, lower shear pins 77 (FIG. 2B) extend radially through and interconnect the lower portion of the sleeve and the second intermediate member 46 of the housing, it being noted that these shear pins pass through the internal wall 49 of the second intermediate member 46 slightly below the lower shoulder 48 thereof. As will be understood, the sleeve is made in two portions, namely, the described upper and lower portions, for enabling assembly of the tool 20.

The retaining sleeve 60 (FIGS. ZB-F) is slidable within the support housing 22 between a lower, retaining position (FIGS. 2B-F) wherein the slots 29 (FIG. 2C) are covered by the upper portion 62 of the sleeve and the lower end 75 (FIG. 2F) is spaced below the radial flange 54 (FIG. 2E) of the housing 22, and a retracted position (FIGS. 3A-E) wherein the windows 64 (FIG. 3C) are individually in registration with their respectively aligned slots 29 and wherein the lower end 75 (FIG. 3B) of the sleeve is closely adjacent to the radial flange 54. That is, in its retracted position, the sleeve is withdrawn upward into the housing from its retaining position. An

upper, sleeve retracting compression spring 80 (FIG. 2B) encircles the upper portion 62 of the sleeve, between the sleeve and the housing, and has upper and lower ends respectively bearing against the end flange 63 of the sleeve and the internal shoulder 28 of the housing. In addition, a lower sleeve retracting compression spring 82 (FIG. 2B) encircles the lower portion 70 of the sleeve between the sleeve and the housing and has upper and lower ends respectively bearing against the upper shoulder 73 (FIGS. 2]), E) of the sleeve and the lower shoulder 48 (FIG. 2E) of the housing. When the sleeve is in its retaining position (FIGS. 2B-F), both of these springs are under considerable compression so that they exert axial forces urging the sleeve into its retracted position. The shear pins 67 and 77, however, maintain the sleeve in its retaining position, against said urging of the springs, but are shearable, in a manner to be described, to enable the springs to thrust the sleeve into its retracted position (FIGS. 3A-E).

Cutter blades (FIGS. 1, 2C, 3C and 4) are located in the slots 29 of the support housing 22 and are pivotally connected to the housing. Each blade has an enlarged mounting portion 91 (FIG. 2C) providing a notch 92 facing the recess 30 that is adjacent to the slot in which the blade is located, and an arcuate shank 94 curved inward toward the sleeve 60 and tapered to a cutting tip 96. A pivot pin 97 extends through the mounting portion 91 and is journalled in the intermediate element 26 of the housing 22 so that each blade is pivotable about its pin in a plane passing radially through the support housing; each blade is pivotable between 'a retracted position (FIG. 2C) wherein the blade is substantially entirely received within its respective slot 24, disposing its cutting tip clear of the sleeve 60, and a cutting position (FIG. 3C) projecting inward from the support housing and through the associated window 64 of the sleeve 60, the cutting the position of the blades being possible only when the sleeve is in its above described retracted position. Blade restraining leaf springs 98 are individually located in the recesses 30, have upper ends connected to the intermediate element 26 of the housing by screws 99, and have curved lower ends fitted in the notches 92 of their respectively adjacent blades; these leaf springs apply torque to their respective blades for a reason that will subsequently be evident.

In order to collectively urge the blades 90 into their cutting positions (FIG. 3C), an actuating tube 160 (FIG. 2C) is slidably mounted on the upper portion 62 of the sleeve 6-0 and between the sleeve 60 and the intermediate and lower elements 26 and 32 of the support housing 22. This tube has an upper, outwardly and upwardly flaring frusto-conical edge 1.02 below the cutting tips 96 of the blades 99. A coiled, blade projecting, compression spring 104 encircles the sleeve 60 between the sleeve and the intern 11 wall 35 of the housing; this spring has a lower end pressing the internal shoulder 34 of the housing and an upper end pressing against the lower edge of the tube 100. Thus, when the sleeve 60 is in its retaining position and the blades are in their retracted positions (FIGS. 2BF), the frustoconical edge of he ube presses against the shanks 94 (FIG. 2C) of the blades immediately adjacent to their cutting tips 96. When the sleeve moves into its retracted position (FIGS. 3A-E), and as the windows 64 come into registration with the slots 29, the spring-urged tube collectively forces the blades into and maintains them in their cutting positions (FIG. 3C). At all times the leaf springs 98 hold the blades against the tube so that positive control of the positions of blades is constantly maintained.

The casing tool 20 also includes a carrier (FIGS. 1 and 2E, 2F) having an upper tubular part 111 (FIG. 2B) coaxially slidably received within the lower section 40 of the support housing 22 between it 'and the sleeve 60. More specifically, this tubular part slidably engages the internal wall 49 of the second intermediate member 46 and the radial flange 54 of the base member 52. Also, this tubular part has an upper end portion 112 connected to the lower shear pins 77 and an outer annular groove 114 in which is seated a snap ring 116. The snap ring projects radially outward and confronts the radial flange 54 of the base member. The carrier also has an outwardly projecting, lower supporting fiange 118, under the radial flange 5 1-, having a plurality of circumferentially spaced, radially extending openings 119 (FiGS. 2F, 5 and 6) therethrough and spaced radial ledges 12ft under these openings forming T-slots. The carrier is movable axially of the housing and the sleeve from a lower limiting position (FIG. 2E), with the snap ring 116 and the radial flange 54 in engagement with each other, to an upper position (FIG. 3E) during which movement of the lower pins 77 are sheared.

A diametrically contractible slip hanger, generally indicated by the numeral 125 (FIGS. 1 and 2F), is supported on the carrier 110 and includes a segmented lower junk ring 126 concentric with the support housing 22; this ring surrounds the sleeve 61 when the latter is in its retaining position. The junk ring is divided into aplurality of arcuate segments 127 that are assembled in ring formation about the sleeve. Considered as a whole, the junk ring has a lower radial end face 129 (FIG. 2F), an outer cylindrical face 130, a lower frusto-conical shoulder 131 interconnecting the end and outer faces, and an annular groove 133 in its outer face.

The slip hanger 125 also includes bolts 136 (FIG. 2F) having stems 137 individually threaded into the junk ring segments 127 and extending upward therefrom alongside of the sleeve 61}. The bolts have heads 138 individually fitted into holes 139 (FIGS. 2F, 5 and 6) of blocks 1413. These blocks are slidably fitted in the openings 119 in the carrier 110 so that they are movable radially of the carrier, it being noted that the blocks slide on the spaced ledges 126 of the carirer and that the stems of the bolts project between these ledges. Shear pins 142 extend through the heads of the bolts and into their respective blocks for releasably connecting the bolts to the blocks and thus to the carrier.

Furthermore, the slip hanger 125 includes arcuate seals 145 (FIG. 2F), of resiliently deformable material such as rubber, individually overlying the ring segments 127 and surrounding their respective stems 137; metallic arcuate thrust elements 146 lying on the seals and also surrounding the stems; and slip bowl segments 148 individually mounted on the thrust elements by the respective bolts 136. Each bowl segment has a lower radial face 150 engaging its respective thrust element 146, an arcuate outer face 152 concentric with the junk ring 126 and having upper and lower grooves 153 therein, an inner oblique face 155 having the shape of a part of a conical frustrum, and a longitudinal bore 156 extending therethrough from the lower face to the oblique face and slidably receiving the stem of its respective bolt 136. The seals, thrust elements and bowl segments are assembled in tubular formation about the sleeve so that the oblique faces of the bowl segments collectively form a frusto-conical, downwardly tapering wedging surface 158 (FIG. 7) concentric with the support housing 22, and so that the sections of the upper and lower grooves 153 are respectively in alignment circumferentially of the hanger 125.

Additionally, the slip hanger 125 includes a plurality of arcuate slips 160 having outer faces 161 complementary to and slidably engaging the oblique faces 155 of the bowl segments 148, serrated inner faces 163, and longitudinal cavities 164 receiving the stems 137 of their respective bolts 136. The slips are slidable upward and downward on their bowl segments between upper positions (FIG. 2F) wherein these inner faces form a cylinder of maximum diameter, and lower positions (FIGS. 13-15) wherein their inner faces form a cylinder of minimum diameter; the bolts guide the slips during this movement and maintain the slips in overlying relation with their respec- ,tive bowl segments by precluding any appreciable circuni ferential movement of the slips relative to the bowls. Endless tension springs 170 (FIG. 2F) are respectively fitted in the grooves 133 and 153 and yieldabliy urge the ring segments 127 and the slip bowl segments 148, and thus the seals 145, the thrust elements 146, the bolts 136, and the slips 160, radially inward toward a contracted position of minimum diameter. With the sleeve 60 in its retaining position, the springs 171] urge the inner faces 163 of the slips into engagement with the lower portion 70 of the sleeve; however, with the slips engaging the sleeve in this manner, the springs are still under tension.

The casing tool 20 of the present invention is particularly suited for hanging casing by remote control in an underwater well. Before the operation of the tool and the present method for hanging casing therewith are described, the environment therefor will be briefly identified with reference to FIGS. 8 and 9. Thus, the well includes a borehole extending down through the ocean floor 181 and a support casing 184 projecting into the borehole and cemented in place, as indicated at 185. A wellhead 187 projects up from the support casing and has an internal annular ledge 188 and an annular groove 189 spaced above the ledge. Conduits 190, 191 and 192 (FIGS. 8,9, and 1113) are connected to the wellhead for a well known purpose. A blow-out preventer and drilling unit 195 has a lower end connected to the wellhead by a clamp 196 and its upper end is connected to a surface conductor 197 (FIG. 8) by means of an adapter 198 threaded onto the lower end of the surface conductor 197 and connected to the upper end of the blow-out preventer by an upper clamp 199. The adapted 198 is noteworthy since it provides an internal annular ledge 260 which cooperates with the subject casing tool 20, in a manner to be explained.

The method of hanging a string of casing 262 (FIG. 8) according to the present ipvention can now be described, it being understood that the operation is carried out by workmen on a barge, pier, or other working platform, not shown, at the surface of the water above the well. In the description of the method, reference is first made to FIG. 8, it being understood that this figure shows the condition of the apparatus after the first several steps of the method have been completed. The first step of the method of the invention is to run a hanger bushing 205 through the conductor 197 and into the wellhead 187 and to land the bushing on the ledge 188. A J-shaped tool, not shown, fitted in J-slots, as 206 (FIG. 9), in the bushing 1s conveniently used for this purpose. It is of significance that this bushing has a lower annular seat 207 and an upper annular seat 208 of slightly larger diameter than the lower seat. Fluid sealing O-rings 210 are fitted in grooves in the bushing and are in fiuid sealing engagement with the wellhead.

The second step of the subject method (FIG. 8) is to run the casing tool 20 into the surface conductor 197. For this purpose, a hanger pipe 215 is threaded onto the upper element 25 (FIGS. 2A and 8) and is used to lower the tool 20 into and through the surface conductor. The tool is suspended within the conductor with the lower shoulder 131 of the tool spaced above the ledge 200 of the adapter 198. A suitable hanger, not shown, is employed for supporting the hanger pipe in the surface conductor. It is to be remembered that the sleeve 60 of the tool 20 is in its retaining position at this time.

In the third step of the present method, the string of casing 202 is run down through the casing tool 20, through the hanger bushing 205 into the support casing 184, and eventually into the borehole 180 below the lower end of the surface casing. The string of casing is made up in the usual manner by attaching joints 220 in end-to-end relation by collars 221.

As the fourth step, a mandrel hanger 225 is attached to the string of casing 202 at a predetermined distance from the lower end of the string which is now down in the borehole 180. The distance between the mandrel hanger and said lower end of the string is determined by the length of the string it is desired to have project from the wellhead 107 down through the borehole. The mandrel hanger includes a generally cylindrical body 226 and a rim 227 projecting radially outward from the body. The rim has circumferential grooves, and O-rings 228 are fitted in these grooves.

In the fifth step of the method, a landing joint 235 is threaded into the mandrel hanger 225 (FIG. 8) and the string of casing 202 is lowered farther until the rim 227 of the mandrel hanger passes through the upper seat 208 and is landed on the lower seat 207 of the hanger bushing 205, (FIG. 9). It is evident, therefore, that the diameter of the rim is less than the diameter of said upper seat.

Assuming that the mandrel hanger 225 is properly landed, the sixth step involves cementing the string of casing 202 by well known procedures. Thereafter, the landing joint 235 is removed from the mandrel hanger and withdrawn from the conductor 197.

As step number seven, the casing tool 20 is withdrawn from the surface conductor 197. Although the tool was initially lowered into a position of readiness, since the mandrel hanger 225 was successfully landed, neither the slip hanger 125 nor the cutter blades 90 were brought into operating positions.

A lock bushing 240 is then run into the surface cnductor 197 in the eighth step of the method (FIG. 9). This lock bushing has a tubular end portion 241 projecting down between the body 226 of the mandrel hanger 225 and the hanger bushing 205, an outer annular shoulder 242 engaging the upper end of the hanger bushing, and an inner annular shoulder 244 over-lying the upper end of the mandrel hanger. The lock bushing also has an outer circumferential groove 245, and spring-actuated lugs 246 are mounted in this groove for radial movement outward into the annular groove 189 in the wellhead 187. The lock bushing has J-slots, as 247, for enabling the bushing to be run into the described position. When the bushing is locked in position by the lugs, it looks down the hanger bushing and the mandrel hanger thereby precluding upward movement of the string of casing 202. The well is now ready for the next drilling or completion operation.

If, the running the string of casing 202 in steps three or five, as discussed above, the casing should stick in the borehole 180, so that it cannot be lowered far enough to land the mandrel hanger 225 in the hanger bushing 205, the alternative method of the invention is adopted, as follows. Assuming that the mandrel hanger, if connected to the string of casing as above described in step number four, is above the cutter blades 90 and cannot be moved down any farther and that there is no collar 221 between the blades and the upper seat 208 of the hanger bushing 205, alternative step number five is to cement the casing string in the position in which it is stuck. After the cement is sufficiently hardened, the string is placed and held under predetermined tension by well known procedures.

As alternative step number six, the casing tool 20 is lowered from its position of readiness by the hanger pipe 215 whereby the shoulder 131 strikes the ledge 200 of the adapter 198 (FIG. 10). Because of the above described, axially slidable connection, the housing 22 moves downward relative to the slip hanger 125 and the carrier 110, both of which are precluded from moving downward by the ledge 200. Thus, the lower shear pins 77 temporarily interconnecting the housing 22, the carrier 110 and the sleeve 60, are sheared (FIG. 3E) whereupon the lower retracting spring 82 forces the lower portion 70 of the sleeve 60 against the upper portion of the sleeve thereby shearing the upper pins 67 and allowing the upper retracting spring 80 to aid the lower spring in forcing the entire sleeve into its retracted position (FIGS. 3A-E). The perforations 74 allow fluid entrapped between the shoulders 44 and 73 to escape so that this fluid does not prevent retracting movement of the sleeve. With the sleeve retracted, the slip hanger 125 diametrically contracts into engagement with the string of casing 202, and the blades pivot into engagement with the string above the slip hanger.

Alternative step number seven is to lower the tool 20, during which movement the slip hanger 125 and blades 90 slide down the engaged joint 220 of the string 202, until the slip hanger is landed (FIG. 11) in the hanger bushing 205, it being noted that the shoulder 131 of the slip hanger rests on the upper seat 208. Tension on the string is then relieved, causing said joint of the string and the slips 160 to move downward relatively to the bowl segments 148. This causes the slips to wedge between the joint and the wedging surface 150 (FIG. 3F). The string of casing is now hung on the slip hanger.

As alternative step number eight (FIG. 11), the hanger pipe 215 is rotated whereby the upper section 24 of the housing 22 rotates relatively to the lower section 40, causing the cutter blades 90 to cut an upper section 202w of the casing string from the remaining or hung section 202/2 of the string. The cutoff upper section is then removed from the surface conductor 197.

The hanger pipe 215 is then raised for alternative step number nine (best visualized in FIGS. 3F, 11 and 12), causing the shear pins 142 to shear, whereupon the housing 22, the sleeve 60 and the carrier are separated from the slip hanger since the latter is retained in the hanger bushing 205 by the weight of the string 20211 pulling downward on the slips 160. Once separated, the tool 20, minus the slip hanger, is removed from the surface conductor 107.

Alternative step number ten (FIG. 13) is to cut off the remaining section 202/1 of the string 202 with an inside casing cutter 250. The casing cutter, although in itself not constituting a part of the present invention. is briefly described in order to convey a more complete understanding of the method. The cutter includes a lower housing 251 projecting down inside the string of casing 202h and held against movement with respect to the string by inside gripping dogs 252 on the lower housing. The casing cutter has an upper housing 254 rotatably connected to the lower housing and mounting cutting knives 255 engaging the inside of the casing string. An outside skirt 257 projects down from the upper housing around the casing string. The skirt has a lower portion 258 resting on the upper end of the hanger bushing 205 and has an upper portion 259 rotatably connected to the lower portion by bearings 260. The inside casing cutter is lowered on a drill pipe 262 into the described position. When in this position, the cutting knives 255 are rotated, and the string of casing is cut oif a predetermined distance above the hanger bushing. After the casing cutter and cut-off portion of casing are removed from the surface conductor 197, the string (1); casing remaining in the well is as illustrated in FIG.

The eleventh or final step of the alternative method is to lower a lock bushing 270 (FIG. 15) into the wellhead 187. The lower end 271 of the bushing engages the upper end of the hanger bushing 205. An intermediate shoulder 272 of the bushing overlies the slip hanger 125, and an inner shoulder 273 overlies the upper, cut edge of the string of casing 202k. The lock bushing also has a circumferential groove, and lugs 275 are mounted in this groove for movement radially outward into the annular groove 189 in the wellhead. The lock bushing also has J-slots, as 276, which facilitate lowering the bushing into the wellhead. Thus, as in step number eight described above in connection with the mandrel hanger 225, the well is now ready for the next drilling or completion operation.

It will be understood from the foregoing description that the present invention provides a method for hanging casing by a mandrel hanger if conditions permit, but which enables the casing to be hung with a slip hanger if the casing cannot be hung with the mandrel hanger. Furthermore, the invention provides a slip-hanger-andcasing-cutter tool that can be supported in a convenient location in the well in readiness for use if needed but which can be removed from such location if the casing is hung with the mandrel hanger. The method and apparatus are especially suited for hanging casing by remote control in an underwater well. If the casing string does not stick in the borehole, it can be hung very simply and economically with a mandrel hanger. On the other hand, if the casing string does stick and precludes landing of the mandrel hanger, the slip hanger is immediately available and can be brought into use, with a minimum of effort and time, as a substitute for the mandrel hanger. The subject method and apparatus also provides for retrieval of whichever hanger is not used.

Although a preferred method and embodiment of the present invention have been described, it will be understood that various changes and modifications may be made in the details thereof without departing from the spirit and the scope of the appended claims.

Having thus described the invention, what is claimed as new and desired to be protected by Letters Patent is:

1. In a method for hanging pipe in a head by using a mandrel hanger or a slip hanger if the mandrel hanger cannot be landed, the steps of installing in said head a hanger bushing adapted to seat either a mandrel hanger or a slip hanger; running pipe through said bushing in said head and into a borehole therebelow; attaching a mandrel hanger to an upper end of the pipe; continuing to run the pipe into the borehole whereby said mandrel hanger is moved closer to said hanger bushing; landing a slip hanger in said hanger bushing about said pipe; supporting said pipe in said slip hanger; and cutting off said pipe above said bushing.

2. In a method for installing casing in an underwater well wherein a tubular member extends down through the water to a head and is connected thereto, the steps of suspending a tubular casing-tool, including a slip hanger and a cutting blade, in the tubular member with the slip hanger spaced above said head; lowering casing, having a lower end, down through said suspended tool, past said blade and slip hanger, and through said head into the well therebelow; attaching a mandrel hanger to said casing so that the distance from said mandrel hanger to said lower end is equal to the distance it is desired to space said lower end below said head; continuing to lower said casing in said well until said mandrel hanger is supported in the head; and removing the casing-tool from the tubular member.

3. In a method for hanging casing in a wellhead member located under water by using a hanger bushing having a seat therein, there being a surface conductor extending from the wellhead member to the surface of the water, the steps of running said hanger bushing through said conductor and landing said bushing in said wellhead member; suspending a tubular tool, including a slip hanger and casing cutter, in said conductor with said slip hanger spaced above said bushing; running casing through said suspended tool and said landed bushing; attaching a mandrel hanger to an upper end of said casing; landing said mandrel hanger on the seat of said bushing thereby supporting said casing on said bushing; and removing said tool from said conductor after said mandrel hanger is landed.

4. In a tool for supporting a casing engaging member in an annulus between an inner casing and an outer conductor and for moving said engaging member into contact with said inner casing, a tubular support adapted to project into said annulus, means mounting said engaging member on said support for movement along a path extending transversely of said support from a retracted position to a casing engaging position spaced radially inward of said retracted position, first means yieldably urging said engaging member toward its engaging position, a retainer positioned within said support and being movable axially thereof between a retaining position in said path of radial movement of said engaging member and a retracted position out of said path, said first urging means being capable of moving said engaging member into its engaging position when said retainer is retracted, second means yieldably urging said retainer toward its retracted position, and releasable means holding said retainer in its retaining position but being releasable to permit said second urging means to move said retainer into its retracted position.

5. In a tool for supporting a casing engaging member in an annulus between an inner casing and an outer conductor and for moving said engaging member into contact with said inner casing, a tubular support adapted to project into said annulus, means mounting said engaging member on said support for movement along a path extending transversely of said support from a retracted position to a casing engaging position spaced radially inward of said retracted position, first means yieldab ly urging said engaging member toward its engaging position, a retainer positioned within said support and being movable axially thereof between a retaining position in said path of radial movement of said engaging member and a retracted position out of said path wherein said first yieldable means moves said engaging member into its engaging position, yieldable means bearing against said retainer and said support and applying a force to said retainer in an axial direction relative to said tubular member thereby urging said retainer toward its retracted position, and releasable means holding said retainer in its retaining position but being releasable to permit said yieldable bearing means to move said retainer into its retracted position.

6. In a tool for supporting a casing engaging member in an annulus between an inner casing and an outer conductor and for moving said engaging member into contact with said inner casing, a tubular support adapted to pro ject into said annulus, means mounting said engaging member on said support for movement along a path extending transversely of said support from a retracted position to :a casing engaging position spaced radially inward of said retracted position, first means yieldably urging said engaging member toward its engaging position, a retainer positioned within said support and being movable axially thereof between a retaining position in said path of radial movement of said engaging member and a retracted position out of said path, said first yieldable means being capable of moving said engaging member into its engaging position when said retainer is in retracted position, second yieldable means bearing against said retainer and said support and applying a force to said retainer. said force being directed axially of said tubular member and urging said retainer toward its retracted position, and means releasably interconnecting said support and said retainer for holding said retainer in its retaining position, said interconnecting means being releasable to permit said second yieldable means to move said retainer into its retracted position.

7. The tool of claim 4 wherein said engaging member is a casing cutter blade disposed lengthwise of said support, and wherein said retainer has a window extending lengthwise of said support so that said blade and window lie in a common plane passing diametrically through said support, said window being in registration with said blade in the retracted position of said retainer.

8. In a well tool, a tubular support having a lower end portion; a sleeve slidably positioned within said support for movement between a retaining position projecting below said lower end portion and a retracted position displaced upward from its retaining position; first means said sleeve between retracted positions engaging said sleeve when the latter is in its retaining position and casing engaging positions spaced radially inward of their retracted positions when said sleeve is in its retracted position, and second means yieldably urging said slips into their casing engaging positions.

9. The tool of claim 8 including means mounting said slip hanger on the lower end of said support for axial movement of said hanger relative to said support, said hanger mounting means being operable to release said holding means upon relative movement of said support and hanger toward each other.

10. The tool of claim 9 wherein said holding means is a shear pin that interconnects said sleeve and said support, said hanger mounting means being axially movable with said hanger, said shear pin lying in the path of movement of said hanger mounting means.

11. The tool of claim 9 wherein said hanger mounting means includes a shear pin adapted to shear upon application of predetermined force that urges said support axially away from said hanger.

12. The tool of claim 8 wherein said tubular support has an annular internal shoulder, wherein said sleeve has an annular external shoulder in confronting relation to said shoulder on said support, and wherein said first urging means is a coiled compression spring positioned be tween said sleeve and said support and bearing against said shoulders.

13. The tool of claim 12' wherein said sleeve is perforated between said shoulders to release entrapped fluid.

14. In a well tool, a tubular support housing including an upper section that has a longitudinally extending slot opening radially therethrough and a lower section rotatably connected to said upper section, a sleeve slidably received within said housing and having a longitudinally extending window therein, said sleeve being axially slidable between a retaining position projecting below said lower section of the housing and with said window displaced from said slot and a retracted position withdrawn upward into said housing and with said window in registration with said slot, a casing cutter blade positioned in said slot and pivoted on said housing for movement in a plane passing radially through said housing between a retracted position substantially entirely in said slot and outward of said sleeve and a cutting position projected into said housing through said window in the sleeve, means yieldably urging said blade into its cutting position and thus toward said sleeve when the latter is in its retaining position, means yieldably urging said sleeve toward its retracted position, means releasably holding said sleeve in its retaining position, annular casing grasping means surrounding and resiliently engaging said sleeve below said housing in the retaining position of said sleeve and being radially inwardly constrictable when said sleeve moves to its retracted position, and means supporting said grasping means on said lower housing section for movement toward and away from said housing and for releasing said holding means upon forceful movement of said grasping means toward said housing.

15. The tool of claim 14 wherein said grasping means includes a plurality of ring segments assembled in ring formation and being endwardly spaced from and concentric with said lower section of the housing, bolts individually connected to said segments and projecting toward said housing, slip bowl segments individually mounted on said bolts, slips individually supported on said bowl segments and a tension spring circumscribing said bowl segments and yieldably urging the same radially inward to press said slips against said sleeve in its retaining position, said supporting means being connected to said bolts.

16. The tool of claim 15 wherein said supporting means includes an annular carrier concentrically slidably fitted between said sleeve and the lower section of said housing, said tool also including means on said lower section of the housing engageable with said carrier for limiting movement of said carrier away from said housing, and wherein said holding means includes a shear pin interconnecting said sleeve and said lower section of said housing and lying in the path of movement of said carrier, said shear pin being sheared by said carrier as the latter moves toward said lower section of the housing.

17. The tool of claim 14 wherein said blade urging means includes a tube concentrically slidably fitted between said sleeve and the upper section of said housing and engaging said blade, and a coiled compression spring concentrically positioned between said sleeve and the upper section of said housing, said spring having an upper end engaging said tube and a lower end engaging said housing and being compressed between said housing and said tube for yieldably urging said blade toward its cutting position.

18. In a Well installation including a head, a hanger bushing supported in said head and being provided with a lower annular seat having an outer diameter and an upper annular seat having an inner diameter larger than said outer diameter; a tubular mandrel hanger having a lower annular shoulder landed on the lower seat of said bushing and defining an annular channel with said upper seat, and an upper portion projecting upward from said shoulder in circumferentially spaced relation to said bushing, said hanger being adapted to connect to and support a string of pipe therefrom; a locking bushing within said head having a lower annular portion projecting between said bushing and the upper portion of said hanger and engaging said upper seat and shoulder in said channel; and means latching said locking bushing in said head.

19. In a well installation including upstanding duct means having an internal annular ledge; an annular radially contractable slip hanger having a lower annular shoulder and being movable between an outer, expanded condition wherein the outer diameter of said shoulder is greater than the inner diameter of said ledge and a con tracted condition wherein said outer diameter of said shoulder is less than said inner diameter of said ledge; means for suspending said hanger in said duct means; means connecting said suspending means to said hanger; means associated with said suspending and connecting means for releasably retaining said hanger in expanded condition, said suspending and connecting means cooperating to release said retaining means to allow the hanger to move into contracted condition when said shoulder bears against said ledge with a predetermined force.

20. The installation of claim 19 including a head, said duct means being connected to said head and projecting upward therefrom, a hanger bushing supported in said head below said ledge and providing an annular seat having an inner diameter less than said outer diameter of said shoulder when said hanger is in its contracted condition whereby said slip hanger can be landed on said seat by said suspending means when the slip hanger is in its contracted condition.

21. In a well installation including a generally upstanding wall means encircling a passageway, a hanger bushing supported within said Wall means and having an upwardly facing annular seat encircling said passageway, said seat having a predetermined minimum diameter, a casing string supported in said passage and projecting through and above said seat, a mandrel hanger connected to said string above said seat, said hanger having a circumferential rim of maximum diameter greater than the minimum diameter of said seat, and a tubular casing engaging member encircling said casing and said mandrel hanger and having an internal diameter greater than said maximum diameter of the mandrel hanger whereby said casing engaging member and said mandrel hanger are relatively movable past each other in said passage.

22. In completing a well, the method of hanging within a well bore a casing apt to get stuck in the well bore before a predetermined length thereof is installed, which method comprises mounting at the top of the well bore a wellhead having upper and lower internal annular upwardly facing shoulders, the upper shoulder being of greater diameter than the lower shoulder, positioning above the wellhead a casing tool including a slip hanger seatable upon said upper shoulder of the wellhead and a casing cutter spaced above the slip hanger, aflixing to the upper end of a casing having said predetermined length a mandrel hanger of smaller diameter than the upper shoulder of the wellhead and seatable upon said lower shoulder, and lowering said casing through the bore of said casing tool and the bore of said wellhead until said hanger is seated on said lower shoulder.

23. In a well installation including upstanding duct means having an internal ledge; an annular radially contractible slip hanger having a lower shoulder and being movable between an outer expanded condition and a contracted condition; means for suspending said hanger in said duct means, means connecting said suspending means to said hanger; means associated with said suspending and connecting means for releasably retaining said hanger in expanded condition, said suspending and connecting means cooperating to release said retaining means to allow the hanger to move into contracted condition when said shoulder bears against said ledge with a predetermined force.

24. The method of installing a casing within a borehole, which comprises mounting at the top of the borehole a wellhead having a lower internal upwardly facing annular shoulder and an upper internal upwardly facing annular shoulder of larger diameter than said lower shoulder; positioning a tubular casing tool above the wellhead and in coaxial relation therewith, said casing tool including a slip hanger seatable upon said upper shoulder of the wellhead and a retracted casing cutter above the slip hanger; lowering a casing through the bore of said casing tool and the bore of the wellhead and as far as possible into the bore hole, said casing having on its upper end a mandrel hanger dimensioned for seating engagement with said lower shoulder; lowering the casing tool, when the casing gets stuck in the borehole before the mandrel hanger seats upon said lower shoulder, until said slip hanger thereof seats upon said upper shoulder thereby actuating the casing tool to advance the slip hanger thereof into supporting engagement with the casing; actuating the casing tool to sever the casing with the casing cutter; and retrieving the severed upper part of the casing and the mandrel hanger thereon.

25. The method of installing a casing within a borehole, which comprises mounting at the top of the borehole a wellhead having a lower internal upwardly facing annular shoulder and an upper internal upwardly facing annular shoulder of larger diameter than said lower shoulder; positioning a tubular casing tool above the wellhead and in coaxial relation therewith, said casing tool including a slip hanger seatable upon said upper shoulder of the wellhead and a removable retracted casing cutter above the slip hanger; lowering a casing through the bore of said casing tool and the bore of the wellhead and as far as possible into the bore hole, said casing having on its upper end a mandrel hanger dimensioned for seating engagement with said lower shoulder; lowering the casing tool, when the casing gets stuck in the borehole before the mandrel hanger seats upon said lower shoulder, until said slip hanger thereof seats upon said upper shoulder thereby actuating the casing tool to advance the slip hanger thereof into supporting engagement with the casing; actuating the casing tool to sever the casing with the casing cutter; retrieving the severed upper part of the casing and the mandrel hanger thereon; and recovering said removable casing cutter.

26. In a well tool, a tubular support having a lower end, a sleeve slidably fitted within said support and having a lower end portion projecting from the lower end of said support, said sleeve being slidably upwardly Within said support to a retracted position, a slip hanger including a plurality of easing gripping portions assembled about said lower end portion of the sleeve, said gripping portions including supporting bolts projecting toward said support, and said hanger further including resilient means yieldably urging said gripping portions radially inward against said sleeve, an annular carrier connected to the lower end of said support in encircling relation to said sleeve, and means individually mounting said bolts on said carrier for movement of said bolts radially of said carrier between a position with said gripping portions on the outside of the lower end portion of said sleeve and a position with said gripping portions projecting radially inward from said carrier when said sleeve is in its retracted position, said carrier including a plurality of radial grooves therein, said bolt mounting means including blocks individually radially slidably fitted in aid grooves and connected to said bolts, and said bolts and locks being interconnected to said bolts, and said bolts and locks being interconnected by shear pins.

References Cited by the Examiner UNITED STATES PATENTS 2,134,311 10/1938 Minor et al. 166-47 2,906,500 9/1959 Knapp et 'al 16666.5 3,054,449 9/1962 Schramm et al 166-665 3,086,590 4/1963 Jackson et a1. -7 3,089,543 4/1963 Raulins 166--75 3,099,317 7/ 1963 Todd 16666.5 3,137,348 6/1964 Ahlstone et al 16688 3,204,695 9/1965 Murray 16655.6

CHARLES E. OCONNELL, Primary Examiner.

C. D. JOHNSON, J. A. LEPPINK, Assistant Examiners. 

1. IN A METHOD FOR HANGING PIPE IN A HEAD BY USING A MANDREL HANGER OR A SLIP HANGER IF THE MANDREL HANGER CANNOT BE LANDED, THE STEPS OF INSTALLING IN SAID HEAD A HANGER BUSHING ADAPTED TO SEAT EITHER A MANDREL HANGER OR A SLIP HANGER; RUNNING PIPE THROUGH SAID BUSHING IN SAID HEAD AND INTO A BOREHOLE THEREBELOW; ATTACHING A MANDREL HANGER TO AN UPPER END OF THE PIPE; CONTINUING TO RUN THE PIPE INTO THE BOREHOLE WHEREBY SAID MANDREL HANGER IS MOVED CLOSER TO SAID HANGER BUSHING; LANDING A SLIP HANGER IN SAID HANGER BUSHING ABOUT SAID PIPE; SUPPORTING SAID PIPE IN SAID SLIP HANGER; AND CUTTING OFF SAID PIPE ABOVE SAID BUSHING.
 4. IN A TOOL FOR SUPPORTING A CASING ENGAGING MEMBER IN AN ANNULUS BETWEEN AN INNER CASING AND AN OUTER CONDUCTOR AND FOR MOVING SAID ENGAGING MEMBER INTO CONTACT WITH SAID INNER CASING, A TUBULAR SUPPORT ADAPTED TO PROJECT INTO SAID ANNULUS, MEANS MOUNTING SAID ENGAGING MEMBER ON SAID SUPPORT FOR MOVEMENT ALONG A PATH EXTENDING TRANSVERSELY OF SAID SUPPORT FROM A RETRATED POSITION TO A CASING ENGAGING POSITION SPACED RADIALLY INWARD OF SAID RETRACTED POSITION, FIRST MEANS YIELDABLY URGING SAID ENGAGING MEMBER TOWARD ITS ENGAGING POSITION, A RETAINER POSITIONED WITHIN SAID SUPPORT AND BEING MOVABLE AXIALLY THEREOF BETWEEN A RETAINING POSITION IN SAID PATH OF RADIAL MOVEMENT OF SAID ENGAGING MEMBER AND A RETRACTED POSITION OUT OF SAID PATH, SAID FIRST URGING MEANS BEING CAPABLE OF MOVING SAID ENGAGING MEMBER INTO ITS ENGAGING POSITION WHEN SAID RETAINER IS RETRACTED, SECOND MEANS YIELDABLY URGING SAID RETAINER TOWARD ITS RETRACTED POSITION, AND RELEASABLE MEANS HOLDING SAID RETAINER IN ITS RETAINING POSITION BUT BEING RELEASABLE TO PERMIT SAID SECOND URGING MEANS TO MOVE SAID RETAINER INTO ITS RETRACTED POSITION. 